java.lang.Throwable: This exception has no message.

java.lang.Throwable: 	at com.intellij.openapi.diagnostic.Logger.error(Logger.java:127)	at com.intellij.openapi.vfs.newvfs.RefreshQueueImpl.execute(RefreshQueueImpl.java:64)	at com.intellij.openapi.vfs.newvfs.RefreshSessionImpl.launch(RefreshSessionImpl.java:120)	at com.intellij.openapi.vfs.newvfs.RefreshQueueImpl.processSingleEvent(RefreshQueueImpl.java:145)	at com.intellij.openapi.vfs.newvfs.impl.VirtualDirectoryImpl.createAndFindChildWithEventFire(VirtualDirectoryImpl.java:254)	at com.intellij.openapi.vfs.newvfs.impl.VirtualDirectoryImpl.findChild(VirtualDirectoryImpl.java:96)	at com.intellij.openapi.vfs.newvfs.impl.VirtualDirectoryImpl.refreshAndFindChild(VirtualDirectoryImpl.java:261)	at com.intellij.openapi.vfs.newvfs.VfsImplUtil.refreshAndFindFileByPath(VfsImplUtil.java:136)	at com.intellij.openapi.vfs.impl.jar.JarFileSystemImpl.refreshAndFindFileByPath(JarFileSystemImpl.java:133)	at com.intellij.openapi.vfs.impl.VirtualFileManagerImpl.refreshAndFindFileByUrl(VirtualFileManagerImpl.java:147)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.IdeaModelLoader.findModuleDescriptorInArtifacts$priv$(IdeaModelLoader.ceylon:211)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.IdeaModelLoader.buildClassMirrorInternal(IdeaModelLoader.ceylon:183)	at com.redhat.ceylon.ide.common.model.BaseIdeModelLoader$11.$call$(IdeModelLoader.ceylon:536)	at com.redhat.ceylon.ide.common.model.BaseIdeModelLoader$11.$call$(IdeModelLoader.ceylon:527)	at com.redhat.ceylon.ide.common.model.BaseIdeModelLoader$1anonymous_0_.call(IdeModelLoader.ceylon:133)	at com.redhat.ceylon.model.loader.AbstractModelLoader$1.call(AbstractModelLoader.java:345)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.IdeaModelLoader.embeddingSync(IdeaModelLoader.ceylon:115)	at com.redhat.ceylon.model.loader.AbstractModelLoader.synchronizedCall(AbstractModelLoader.java:341)	at com.redhat.ceylon.ide.common.model.BaseIdeModelLoader.callWithLock(IdeModelLoader.ceylon:132)	at com.redhat.ceylon.ide.common.model.BaseIdeModelLoader.lookupNewClassMirror(IdeModelLoader.ceylon:566)	at com.redhat.ceylon.model.loader.AbstractModelLoader$3.call(AbstractModelLoader.java:433)	at com.redhat.ceylon.model.loader.AbstractModelLoader$3.call(AbstractModelLoader.java:404)	at com.redhat.ceylon.model.loader.AbstractModelLoader$1.call(AbstractModelLoader.java:345)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.IdeaModelLoader.embeddingSync(IdeaModelLoader.ceylon:115)	at com.redhat.ceylon.model.loader.AbstractModelLoader.synchronizedCall(AbstractModelLoader.java:341)	at com.redhat.ceylon.model.loader.AbstractModelLoader.lookupClassMirror(AbstractModelLoader.java:404)	at com.redhat.ceylon.model.loader.AbstractModelLoader.loadClass(AbstractModelLoader.java:598)	at com.redhat.ceylon.model.loader.AbstractModelLoader.access$800(AbstractModelLoader.java:100)	at com.redhat.ceylon.model.loader.AbstractModelLoader$10.call(AbstractModelLoader.java:2132)	at com.redhat.ceylon.model.loader.AbstractModelLoader$10.call(AbstractModelLoader.java:2119)	at com.redhat.ceylon.model.loader.AbstractModelLoader$1.call(AbstractModelLoader.java:345)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.IdeaModelLoader$1$1.$call$(IdeaModelLoader.ceylon:103)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.concurrencyManager_.withIndexStrategy$priv$(concurrencyManager.ceylon:192)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.concurrencyManager_.outsideDumbMode(concurrencyManager.ceylon:223)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.IdeaModelLoader$1.$call$(IdeaModelLoader.ceylon:102)	at ceylon.interop.java.JavaRunnable.run(JavaRunnable.ceylon:7)	at com.intellij.openapi.project.DumbService$2.compute(DumbService.java:125)	at com.intellij.openapi.project.DumbService$2.compute(DumbService.java:119)	at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:966)	at com.intellij.openapi.project.DumbService.runReadActionInSmartMode(DumbService.java:119)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.IdeaModelLoader.embeddingSync(IdeaModelLoader.ceylon:101)	at com.redhat.ceylon.model.loader.AbstractModelLoader.synchronizedCall(AbstractModelLoader.java:341)	at com.redhat.ceylon.model.loader.AbstractModelLoader.loadCompiledModule(AbstractModelLoader.java:2119)	at com.redhat.ceylon.model.loader.AbstractModelLoader.loadCompiledModule(AbstractModelLoader.java:2115)	at com.redhat.ceylon.compiler.java.loader.model.LazyModuleSourceMapper.resolveModule(LazyModuleSourceMapper.java:128)	at com.redhat.ceylon.ide.common.model.BaseIdeModuleSourceMapper.resolveModule(IdeModuleSourceMapper.ceylon:148)	at com.redhat.ceylon.compiler.typechecker.analyzer.ModuleValidator.resolveModuleIfRequired(ModuleValidator.java:302)	at com.redhat.ceylon.compiler.typechecker.analyzer.ModuleValidator.verifyModuleDependencyTree(ModuleValidator.java:226)	at com.redhat.ceylon.compiler.typechecker.analyzer.ModuleValidator.access$500(ModuleValidator.java:39)	at com.redhat.ceylon.compiler.typechecker.analyzer.ModuleValidator$2.run(ModuleValidator.java:118)	at com.redhat.ceylon.model.typechecker.context.TypeCache.doWithExplicitCaching(TypeCache.java:50)	at com.redhat.ceylon.model.typechecker.context.TypeCache.doWithoutCaching(TypeCache.java:75)	at com.redhat.ceylon.compiler.typechecker.analyzer.ModuleValidator.verifyModuleDependencyTree(ModuleValidator.java:97)	at com.redhat.ceylon.ide.common.model.CeylonProject$16$1.$call$(CeylonProject.ceylon:918)	at com.redhat.ceylon.ide.common.model.withCeylonModelCaching_.withCeylonModelCaching(CeylonProjects.ceylon:47)	at com.redhat.ceylon.ide.common.model.CeylonProject$16.$call$(CeylonProject.ceylon:753)	at com.redhat.ceylon.ide.common.model.BaseCeylonProject.withSourceModel$canonical$(CeylonProject.ceylon:440)	at com.redhat.ceylon.ide.common.model.BaseCeylonProject.withSourceModel(CeylonProject.ceylon:432)	at com.redhat.ceylon.ide.common.model.CeylonProject.parseCeylonModel(CeylonProject.ceylon:750)	at com.redhat.ceylon.ide.common.model.CeylonProjectBuild.resolveClasspath$priv$(CeylonProjectBuild.ceylon:572)	at com.redhat.ceylon.ide.common.model.CeylonProjectBuild.performBuild$canonical$(CeylonProjectBuild.ceylon:587)	at com.redhat.ceylon.ide.common.model.CeylonProjectBuild.performBuild(CeylonProjectBuild.ceylon:578)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.CeylonModelManager$2$2$1anonymous_3_$1.$call$(CeylonModelManager.ceylon:386)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.concurrencyManager_.withIndexStrategy$priv$(concurrencyManager.ceylon:192)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.concurrencyManager_.withUpToDateIndexes(concurrencyManager.ceylon:213)	at org.intellij.plugins.ceylon.ide.ceylonCode.model.CeylonModelManager$2$2$1anonymous_3_.run(CeylonModelManager.ceylon:382)	at com.intellij.openapi.progress.impl.CoreProgressManager$TaskRunnable.run(CoreProgressManager.java:563)	at com.intellij.openapi.progress.impl.CoreProgressManager$2.run(CoreProgressManager.java:142)	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:446)	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:392)	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:54)	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:127)	at com.intellij.openapi.progress.impl.ProgressManagerImpl$1.run(ProgressManagerImpl.java:126)	at com.intellij.openapi.application.impl.ApplicationImpl$8.run(ApplicationImpl.java:369)	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)	at java.util.concurrent.FutureTask.run(FutureTask.java:266)	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)	at java.lang.Thread.run(Thread.java:745)